One of the basic tenets of performing surgery is knowledge of the relevant anatomy. Surgeons incorporate this knowledge along with factors, such as biomechanics and physiology, to develop their operative approaches and procedures. In the diagnosis and management of sacral tumors, the need to be familiar with the anatomy of the sacrum is no less important than knowledge of the pathological entity involved. This article will provide an overview of the embryology and anatomy of the sacrum, along with concepts as applied to surgical intervention.
Joseph S. Cheng and John K. Song
Joseph F. Cusick, Khang-Cheng Ho and Jay F. Schamberg
✓ Subarachnoid hemorrhage is a frequent finding in patients who have incurred neurological complications following chymopapain chemonucleolysis, but the basis for this occurrence remains controversial. The authors report the clinical and postmortem findings in a 42-year-old man who died 5 days after chemonucleolysis at the L4–5 and L5–S1 disc spaces. The predominant histological abnormality was a severe inflammatory arteritis of a medium-sized artery at the upper cervical level with disruption of the vessel wall. The potential causative role of chymopapain in this situation and the correlation of a vascular basis for many of the complications found after inadvertent intrathecal chymopapain injection are discussed.
Daniel M. Oberer, Oran S. Aaronson and Joseph S. Cheng
✓ The authors describe a previously undocumented complication of suboccipital craniectomy combined with duraplasty for the treatment of Chiari malformation Type I and propose techniques to prevent its occurrence. Although there have been reports of epidural pseudomeningoceles in the setting of spontaneous intracranial hypotension and intracranial hygromas following suboccipital craniectomy with duraplasty, the authors believe this case to be the first instance of quadriparesis caused by the delayed formation of a compressive epidural cerebrospinal fluid collection after suboccipital craniectomy with duraplasty. This complication is significant and must be recognized given the potential severity of neurological insult and the number of these procedures performed yearly in both the pediatric and adult populations.
Joseph F. Cusick, Khang-Cheng Ho, Thad C. Hagen and Larry E. Kun
✓ Granular-cell pituicytomas of the neurohypophysis have a controversial histogenesis and oncological behavior. The occurrence of such a tumor in a patient whose father and daughter had endocrine neoplasms suggests a neuroectodermal origin for these tumors. Although all of the conditions considered in this report are unusual clinical entities, their correlation offers considerations in understanding the importance of genetic factors in tumor development.
Jonathan A. Forbes, Ahmed J. Awad, Scott Zuckerman, Kevin Carr and Joseph S. Cheng
The authors' goal was to better define the relationship between biomechanical parameters of a helmeted collision and the likelihood of concussion.
The English-language literature was reviewed in search of scholarly articles describing the rotational and translational accelerations observed during all monitored impact conditions that resulted in concussion at all levels of American football.
High school players who suffer concussion experience an average of 93.9g of translational acceleration (TA) and 6505.2 rad/s2 of rotational acceleration (RA). College athletes experience an average of 118.4g of TA and 5311.6 rad/s2 of RA. While approximately 3% of collisions are associated with TAs greater than the mean TA associated with concussion, only about 0.02% of collisions actually result in a concussion. Associated variables that determine whether a player who experiences a severe collision also experiences a concussion remain hypothetical at present.
The ability to reliably predict the incidence of concussion based purely on biomechanical data remains elusive. This study provides novel, important information that helps to quantify the relative insignificance of biomechanical parameters in prediction of concussion risk. Further research will be necessary to better define other factors that predispose to concussion.
Matthew J. McGirt, Theodore Speroff, Saniya Siraj Godil, Joseph S. Cheng, Nathan R. Selden and Anthony L. Asher
In terms of policy, research, quality improvement, and practice-based learning, there are essential principles—namely, quality, effectiveness, and value of care—needed to navigate changes in the current and future US health care environment. Patient-centered outcome measurement lies at the core of all 3 principles. Multiple measures of disease-specific disability, generic health-related quality of life, and preference-based health state have been introduced to quantify disease impact and define effectiveness of care. This paper reviews the basic principles of patient outcome measurement and commonly used outcome instruments. The authors provide examples of how utilization of outcome measurement tools in everyday neurosurgical practice can facilitate practice-based learning, quality improvement, and real-world comparative effectiveness research, as well as promote the value of neurosurgical care.
Asdrubal Falavigna, Nicolas Scheverin, Orlando Righesso, Alisson R. Teles, Maria Carolina Gullo, Joseph S. Cheng and K. Daniel Riew
Lumbar discectomy is one of the most common surgical spine procedures. In order to understand the value of this surgical care, it is important to understand the costs to the health care system and patient for good results. The objective of this study was to evaluate for the first time the cost-effectiveness of spine surgery in Latin America for lumbar discectomy in terms of cost per quality-adjusted life year (QALY) gained for patients in Brazil.
The authors performed a prospective cohort study involving 143 consecutive patients who underwent open discectomy for lumbar disc herniation (LDH). Patient-reported outcomes were assessed utilizing the SF-6D, which is derived from a 12-month variation of the SF-36. Direct medical costs included medical reimbursement, costs of hospital care, and overall resource consumption. Disability losses were considered indirect costs. A 4-year horizon with 3% discounting was applied to health-utilities estimates. Sensitivity analysis was performed by varying utility gain by 20%. The costs were expressed in Reais (R$) and US dollars ($), applying an exchange rate of 2.4:1 (the rate at the time of manuscript preparation).
The direct and indirect costs of open lumbar discectomy were estimated at an average of R$3426.72 ($1427.80) and R$2027.67 ($844.86), respectively. The mean total cost of treatment was estimated at R$5454.40 ($2272.66) (SD R$2709.17 [$1128.82]). The SF-6D utility gain was 0.044 (95% CI 0.03197–0.05923, p = 0.017) at 12 months. The 4-year discounted QALY gain was 0.176928. The estimated cost-utility ratio was R$30,828.35 ($12,845.14) per QALY gained. The sensitivity analysis showed a range of R$25,690.29 ($10,714.28) to R$38,535.44 ($16,056.43) per QALY gained.
The use of open lumbar discectomy to treat LDH is associated with a significant improvement in patient outcomes as measured by the SF-6D. Open lumbar discectomy performed in the Brazilian supplementary health care system provides a cost-utility ratio of R$30,828.35 ($12,845.14) per QALY. The value of acceptable cost-effectiveness will vary by country and region.
Geriatric comanagement reduces perioperative complications and shortens duration of hospital stay after lumbar spine surgery: a prospective single-institution experience
Presented at the 2017 AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves
Owoicho Adogwa, Aladine A. Elsamadicy, Victoria D. Vuong, Jessica Moreno, Joseph Cheng, Isaac O. Karikari and Carlos A. Bagley
Geriatric patients undergoing lumbar spine surgery have unique needs due to the physiological changes of aging. They are at risk for adverse outcomes such as delirium, infection, and iatrogenic complications, and these complications, in turn, contribute to the risk of functional decline, nursing home admission, and death. Whether preoperative and perioperative comanagement by a geriatrician reduces the incidence of in-hospital complications and length of in-hospital stay after elective lumbar spine surgery remains unknown.
A unique model of comanagement for elderly patients undergoing lumbar fusion surgery was implemented at a major academic medical center. The Perioperative Optimization of Senior Health (POSH) program was launched with the aim of improving outcomes in elderly patients (> 65 years old) undergoing complex lumbar spine surgery. In this model, a geriatrician evaluates elderly patients preoperatively, in addition to performing routine preoperative anesthesia surgical screening, and comanages them daily throughout the course of their hospital stay to manage medical comorbid conditions and coordinate multidisciplinary rehabilitation along with the neurosurgical team. The first 100 cases were retrospectively reviewed after initiation of the POSH protocol and compared with the immediately preceding 25 cases to assess the incidence of perioperative complications and clinical outcomes.
One hundred twenty-five patients undergoing lumbar decompression and fusion were enrolled in this pilot program. Baseline characteristics were similar between both cohorts. The mean length of in-hospital stay was 30% shorter in the POSH cohort (6.13 vs 8.72 days; p = 0.06). The mean duration of time between surgery and patient mobilization was significantly shorter in the POSH cohort compared with the non-POSH cohort (1.57 days vs 2.77 days; p = 0.02), and the number of steps ambulated on day of discharge was 2-fold higher in the POSH cohort (p = 0.04). Compared with the non-POSH cohort, the majority of patients in the POSH cohort were discharged to home (24% vs 54%; p = 0.01).
Geriatric comanagement reduces the incidence of postoperative complications, shortens the duration of in-hospital stay, and contributes to improved perioperative functional status in elderly patients undergoing elective spinal surgery for the correction of adult degenerative scoliosis.
Comparison of cervical spine kinematics using a fluoroscopic model for adjacent segment degeneration
Invited submission from the Joint Section on Disorders of the Spine and Peripheral Nerves, March 2007
Joseph S. Cheng, Fei Liu, Richard D. Komistek, Mohamed R. Mahfouz, Adrija Sharma and Diana Glaser
In this cervical spine kinematics study the authors evaluate the motions and forces in the normal, degenerative, and fused states to assess how alteration in the cervical motion segment affects adjacent segment degeneration and spondylosis.
Fluoroscopic images obtained in 30 individuals (10 in each group with disease at C5–6) undergoing flexion/extension motions were collected. Kinematic data were obtained from the fluoroscopic images and analyzed with an inverse dynamic mathematical model of the cervical spine that was developed for this analysis.
During 20° flexion to 15° extension, average relative angles at the adjacent levels of C6–7 and C4–5 in the fused patients were 13.4° and 8.8° versus 3.7° and 4.8° in the healthy individuals. Differences at C3–4 averaged only about 1°. Maximum transverse forces in the fused spines were two times the skull weight at C6–7 and one times the skull weight at C4–5, compared with 0.2 times the skull weight and 0.3 times the skull weight in the healthy individuals. Vertical forces ranged from 1.6 to 2.6 times the skull weight at C6–7 and from 1.2 to 2.5 times the skull weight at C4–5 in the patients who had undergone fusion, and from 1.4 to 3.1 times the skull weight and from 0.9 to 3.3 times the skull weight, respectively, in the volunteers.
Adjacent-segment degeneration may occur in patients with fusion due to increased motions and forces at both adjacent levels when compared with healthy individuals in a comparable flexion and extension range.
Debraj Mukherjee, Kaisorn L. Chaichana, Ziya L. Gokaslan, Oran Aaronson, Joseph S. Cheng and Matthew J. McGirt
Malignant primary osseous spinal neoplasms are aggressive tumors that remain associated with poor outcomes despite aggressive multidisciplinary treatment measures. To date, prognosis for patients with these tumors is based on results from small single-center patient series and controlled trials. Large population-based observational studies are lacking. To assess national trends in histology-specific survival, the authors reviewed patient survival data spanning 30 years (1973–2003) from the Surveillance, Epidemiology, and End Results (SEER) registry, a US population-based cancer registry.
The SEER registry was queried to identify cases of histologically confirmed primary spinal chordoma, chondrosarcoma, osteosarcoma, or Ewing sarcoma using coding from the International Classification of Disease for Oncology, Third Edition. Association of survival with histology, metastasis status, tumor site, and year of diagnosis was assessed using Cox proportional-hazards regression analysis.
A total of 1892 patients were identified with primary osseous spinal neoplasms (414 with chordomas, 579 with chondrosarcomas, 430 with osteosarcomas, and 469 with Ewing sarcomas). Chordomas presented in older patients (60 ± 17 years; p < 0.01) whereas Ewing sarcoma presented in younger patients (19 ± 11 years; p < 0.01) compared with patients with all other tumors. The relative incidence of each tumor type remained similar per decade from 1973 to 2003. African Americans comprised a significantly greater proportion of patients with osteosarcomas than other tumors (9.6% vs 3.5%, respectively; p < 0.01). Compared with the sacrum, the mobile spine was more likely to be the site of tumor location for chordomas than for all other tumors (47% vs 23%, respectively; p < 0.05). Osteosarcoma and Ewing sarcoma were 3 times more likely than chondrosarcoma and chordoma to present with metastasis (31% vs 8%, respectively). Resection was performed more frequently for chordoma (88%) and chondrosarcoma (89%) than for osteosarcoma (61%) and Ewing sarcoma (53%). Overall median survival was histology-specific (osteosarcoma, 11 months; Ewing sarcoma, 26 months; chondrosarcoma, 37 months; chordoma, 50 months) and significantly worse in patients with metastasis at presentation for all tumor types. Survival did not significantly differ as a function of site (mobile spine vs sacrum/pelvis) for any tumor type, but more recent year of diagnosis was associated with improved survival for isolated spinal Ewing sarcoma (hazard ration [HR] 0.95; p = 0.001), chondrosarcoma (HR 0.98; p = 0.009), and chordoma (HR 0.98; p = 0.10), but not osteosarcoma.
In this analysis of a 30-year, US population-based cancer registry (SEER), the authors provide nationally representative prognosis and survival data for patients with malignant primary spinal osseous neoplasms. Overall patient survival has improved for isolated spine tumors with advancements in care over the past 4 decades. These results may be helpful in providing historical controls for understanding the efficacy of new treatment paradigms, patient education, and guiding level of aggressiveness in treatment strategies.